For every person who felt themselves swept up by the vast tapestry of James Cameron's Avatar, with its USBed-up alien creatures and gorgeous CGI vistas, there's another who sees the whole project as the evil embodiment of everything that's wrong with Hollywood: soulless, cliched and reliant on spectacle over storyline. Those who find themselves in the latter camp will not have been heartened by an MTV interview with Cameron late last week, in which he further outlined his plans for taking the series forward. The rest of us? Well it sounds pretty promising, with a few notable exceptions.

For the most part, Cameron was talking about the forthcoming big screen re-release of the first Avatar film, which does sort of sound a little bit like an opportunity to tap up the average punter for yet more money. There will be nine minutes of extra footage in the new version, but why didn't we get to see this in the recent DVD cut? The most notable addition is the notorious Na'avi sex scene in which Jake and Neytiri get it on, alien style, but it hardly sounds like we're talking Pandoran porn.

"I would say, just so that we correctly manage people's expectations, it does not change our rating at all," Cameron told MTV. "I would call it more of an alien foreplay scene. It's not like they're ripping their clothes off and going at it. It lasts all of about 20 seconds."

Other additions include a scene in the forest, where various Na'avi have gathered to witness the death of Tsu'Tey following his fall from the shuttle after a brave assault high in the skies, and a hunt scene in which the locals track a herd of previously unseen creatures known as Sturmbeests.

It seems likely that the next two Avatar films will be shot back-to-back, though the film-maker is suggesting he'll be able to avoid the pitfalls of other series which have followed a similar route.

"That is something that makes a lot of sense, given the nature of these productions, because we can bank all the [motion] capture and then go back and do cameras over a period of time," said Cameron. "The way these back-to-back productions fall apart is that you're trying to do two live-action films back to back, and you're working on it for a year and a half, shooting. Everyone is dead. It's not humanly possible. This type of film, it absolutely would work."

Cameron has also been talking about his plans for two previously announced sequels, as well as the novel he's currently writing, which will set the ground rules for the Avatar universe. The aim is to avoid "a cheesy novelisation, where some hack comes in and kind of makes shit up", and produce "a legitimate novel that was inside the characters' heads and didn't have the wrong culture stuff, the wrong language stuff, all that".

"I don't mind opening the universe, but I just don't want that to happen until I've got more meat on the bones," said Cameron. "That all needs to be filled in before other writers can come in and run with it."

All of which sounds rather like the film-maker might be planning to let Avatar run and run, perhaps even beyond the three movies currently planned. Given that he's got entire systems to explore, and almost infinite resources with which to do so, there seems to be little reason to cut matters short. Still, most film series work best as trilogies, as Christopher Nolan has duly noted with the current Batman franchise. It makes sense that Cameron wants to get the basics right, given the mess that other film-makers have made of the Terminator and Alien series, both of which he had a major role in. But once he takes his hand off the tiller, it might still be hard to avoid the law of diminishing returns.

Does Avatar strike you as the sort of series that could still be extant in 20 or 30 years time? Or should Cameron wrap things up in three movies?